This project is concerned with the design, development and initial testing of a mass spectrometer system to provide quantitative measurements of the distribution of ventilation to perfusion in the normal and diseased lung. The goals for the first year have been to develop techniques in this analysis. These included development of techniques to measure blood: gas solubilities with mass spectrometer and the investigation of the permeability characteristics of various biopolymers which can be used as catheter membranes at later stages in the project. In addition, effort has been placed in the area of multicomponent lung modelling with a view to analyses and significance of the experimental data to be obtained. Goals for the coming year are to use the techniques developed to obtain blood: gas partition coefficients for Halothane, Ether, Nitrous Oxide, Acetone and Sulfur Hexafluoride and to evaluate the permeability of these fluids through several biopolymers.